HOP 0482

HOP No.

HOP title

HOP 0482

[SOOP: R_SMALL_HRES_LCAD_Composition-vs-Height] Tracking the composition through the solar atmosphere layers

abstract of observational proposal

Main Objective: The main goal is to map the abundance of minor ions as a function of height in the solar atmosphere from the upper chromosphere to the corona using IRIS, SPICE and EIS to cover most of the solar atmosphere layers.

Scientific Justification: The use of multi-spectrometer observations which cover different ranges of temperatures in the solar atmosphere will allow to track the composition through the different layers and to identify empirically where the fractionation happens. This is very important in order to distinguish between slow and fast wind.

request to EIS

EIS studies would ideally run together with SPICE study defined by the
R_SMALL_HRES_LCAD_Composition-vs-Height SOOP.

This SOOP will run on 18-19 March 2024 at disk centre as seen from Solar Orbiter, but it will be close to the Earth-Sun line.

SPICE will do the following:
- Spectral Atlas 2 repeats on 18/03/2024 01:00-06:37
- Composition map on 18/03/2024 06:40-13:06
- Spectral Atlas 2 repeats on 18/03/2024 13:09-18:46
- Composition map on 19/03/2024 03:28-09:54

EIS Requests:
- Atlas_120 ID 405, 1 repeat during the first set of Spectral Atlas
- Atlas_180 ID 620, 2 repeats during the first Composition map
- Atlas_120 ID 405, 1 repeat during the second set of Spectral Atlas
- Atlas_180 ID 620, 2 repeats during the second Composition map

Priorities:
- Either Atlas_120 ID 405 on 18/03/2024 from 01:00 or on 18/03/2024 from 13:09.
Either is OK for SPICE.
- One repeat only of Atlas_180 ID 620 on18/03/2024 from 06:40 and one repeat only on 19/03/2024 from 03:28.

If this is still too much for telemetry constraints then the Atlas_180 ID 620 on18/03/2024 from 06:40 should be prioritised.

remarks

Dates: 1. 18/03/2024-19/03/2024 as the SOOP will run on those dates.
2. 2 days.
3. The days are fixed as for Solar Orbiter plan.

Time window: 1. 17 hours and 46 minutes on 18/03/2024: from 01:00 to 18:46 and 6 hours and 26 minutes on 19/03/2024: from 03:28 to 09:54.
See EIS requests for details.
2. Yes

Target(s) of interest: 1., 2., 3. On-disk as for Solar Orbiter plan.

Previous HOPs: No previous HOP submission.

Additional remarks:
The precise target coordinates on 18 and 19 March 2024 will be known well in advance. If there is a lack of telemetry available for EIS, one or both of the instances of Atlas_180 could be reduced to 1 repeat. One of the instances of Atlas_120 could also be removed if necessary.